As soon as one country is left on its own, no country will feel secure after that

Interview: President Toomas Hendrik Ilves tells the Telegraph the time has come for Nato to deter Russia by permanently stationing combat units in the Baltic states

The most sensitive border in Europe lies 130 miles east of Estonia’s elegant presidential palace. Elsewhere, the threat posed by Russia might seem academic or even alarmist, but for President Toomas Hendrik Ilves, the possibility of Estonia becoming the epicentre of the world’s next crisis is very real.

But if the Kremlin were to invade this nation of 1.3 million people in the way it has dismembered Ukraine, the consequences would be infinitely more perilous. Estonia joined Nato 11 years ago - as such, every country in the Atlantic Alliance, including America and Britain, would be obliged to go to war in its defence.

The frontier with Russia, only a two-hour drive from Mr Ilves’s office, also amounts to a nuclear tripwire. And yet not a single American or Nato soldier is currently defending that border.

“We have observed a dramatic increase in military flights,” he says. “We have seen massive snap exercises at our borders. We have seen a heightened level of antagonistic rhetoric and threatening rhetoric where Estonia is not singled out, but we are part of a group of countries who are mentioned in a threatening way.”

Despite the crisis in Ukraine and the ceaseless belligerence of Vladimir Putin, Nato has not permanently deployed any combat units in Estonia or any other Baltic member.

That is because in 1997, Nato signed a “founding act” with Russia stating that no combat troops would be permanently stationed east of Germany “in the current and foreseeable security environment”. In the face of every Russian provocation and threat, Nato is still observing that self-denying ordinance. One company of US infantry, consisting of 150 soldiers, is the sole contingent of Nato troops currently in Estonia – and they are only here temporarily.